The wings of an aircraft are flexible. Bending and twisting of the wings during flight can, in turn, create unwanted additional drag to the aircraft, particularly, during a cruise portion of the flight. Additional drag to the aircraft results in an increase in fuel consumption which results in higher operational costs.
During long flights, for example, an aircraft consumes quantities of fuel which, in turn, changes the overall weight of the aircraft. This change in the weight loading of the aircraft also affects the required aerodynamic lift needed to be applied to the wings to keep the aircraft in trimmed flight. These changes in the weight load and aerodynamic lift conditions of the aircraft during cruise can result in imparting deflection to portions of the wing relative to the fuselage and also in imparting twist to the wing relative to the fuselage. These changing conditions of weight loading and aerodynamic lift forces during cruise flight can also impart a change to the flight angle-of-attack of the aircraft which can also result in adding additional drag to the aircraft.
With the occurrence of deflecting or bending and twisting of portions of the wings during flight, there is a need to monitor the wings during flight to detect and measure or ascertain portions of the wing which are deflecting and twisting relative to the fuselage. With being able to detect and ascertain the amount of deflecting and twisting incurred by portions of the wings during flight, this information provides an opportunity to apply corrective measures to counter the deflecting and twisting of portions of the wings so as to provide a beneficial configuration to the wings in order reduce or eliminate the wings imparting additional drag to the aircraft. A reduction of drag, as mentioned above, will provide a reduction in fuel consumption and reduction in operational costs.
With more aircraft now being constructed of composite material, the wings that are being constructed of composite material tend to experience more pronounced movement and bending during operation. This more pronounced movement by wings further enhances a need to monitor the deflecting and twisting of the wings during flight. Monitoring the deflection and twisting configurations of the wings will assist in determining what corrective modifications would need to be made to the configuration of the wings during flight in order to obtain optimal and efficient operational performance of the aircraft. Again, modification to the configuration of the wings to reduce the occurrence of deflection and twist, as mentioned above, reduces or eliminates the creation of additional drag to the aircraft providing reduced operational costs.
Cameras and markers on the wings have been employed to observe a particular configuration of the wings of a test or experimental aircraft during flight operation or during flight simulation. However, utilizing a camera during flight operations will not be at times practical or useful. Optical detection can be impaired, for example, at altitudes where adverse weather conditions may occur. Also, poor or diminished light conditions can also impair the camera optical detection performance with respect to observing the configuration of the wings during flight.